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- Plasma modification (5)
- Functional groups (3)
- Introduction of functional groups (3)
- Peel strength (3)
- Pulsed plasma (3)
- Pulsed plasma polymerization (3)
- Acrylic acid (2)
- Allyl alcohol (2)
- Allylamine (2)
- Aluminium (2)
- Metal-polymer systems (2)
- Plasma polymerization (2)
- Polypropylene (2)
- Reactions at polymer surfaces (2)
- r.f. pulsed plasma (2)
- Adhesion (1)
- Adhesion promoters (1)
- Adhesion promoting interlayers (1)
- Adhesion-promoting interlayers (1)
- Adhesion-promoting plasma polymer layers (1)
- Al-functional group interactions (1)
- Attenuated total reflectance-Fourier transorm infrared spectroscopy (1)
- Charcterization of homo- and copolymers (1)
- Chemical conversion of functional groups (1)
- Chemical reduction of functional groups (1)
- Co-polymers (1)
- Conducting films (1)
- Cone calorimeter (1)
- Copolymers (1)
- Degradation (1)
- Doping with metal atoms (1)
- ESCA/XPS (1)
- Encapsulation of nanoparticles (1)
- Flame retardance (1)
- Fluorination kinetics (1)
- Gas phase fluorination of PE (1)
- Grafting (1)
- Heat release (1)
- Long-term stability (1)
- Metal-polymer composites (1)
- Metal-polymer interactions (1)
- Metal-polymer interface (1)
- Oxygen low-pressure plasma treatment of polymers (1)
- PET (1)
- Photoelectron spectroscopy (1)
- Plasma (1)
- Plasma bromination (1)
- Plasma polymer (1)
- Plasma polymers with functional groups (1)
- Plasma surface treatment (1)
- Plasma treatment (1)
- Plasma-initiated copolymerization (1)
- Poly(ethylene terephthalate) (1)
- Poly(propylene) (PP) (1)
- Poly(tetrafluoroethylene) (1)
- Polyamides (1)
- Polyethylene (1)
- Polymer surfaces (1)
- Polymer-metal composites (1)
- Reactions at Polymer surfaces (1)
- Selective plasma process (1)
- Spacer (1)
- Spacers (1)
- Surface modification (1)
- Surfaces (1)
- Weathering (1)
- X-ray (1)
- X-ray photoelectron spectroscopy (1)
Communication: Fire retardant coatings are deposited on polyamide-66 using plasma polymerisation. Chemical composition and thickness of deposits are adjusted varying the plasma treatment based on hexamethydisiloxane mixed with oxygen. The fire retardancy performances are evaluated using a cone calorimeter. The correlation between fire retardancy and thickness as well as chemical composition is discussed.
Eine neue Generation von alterungsbeständigen Plasmapolymeren mit definierter chemischer Struktur
(2000)
Technical waxes and paraffins were investigated using supercritical fluid chromatography (SFC), matrix-assisted laser-desorption/ionization mass spectrometry (MALDI-MS) and size-exclusion chromatography (SEC). SEC enables the simultaneous determination of molecular masses up to high values and molecular mass distributions. The resolution of homologous species, however, is poor. In this respect the use of SFC is advantageous. Proper resolution of homologues may be provided up to Mr~1200 without great difficulty. To compare these chromatographic results MALDI-MS was applied for the determination of molecular masses and mass distributions in technical waxes for the first time. Using reflectron mode excellent MALDI mass spectra could be achieved in the molecular mass range up to 1000 Da. The mean values of the molecular masses calculated by MALDI-MS were in sufficient agreement with those of SFC. In the linear mode of MALDI-MS molecular masses could be determined to nearly 3000 Da. Beyond this mass range SEC still remains the method of choice. Advantages and difficulties of the used methods are discussed in this paper.
Polymer surfaces can be finished with functional groups upon exposure to a plasma. Species of the plasma gas are attached at surface carbon atoms, forming functional groups of different composition. To produce a modified polymer surface with a high density and homogeneity of hydroxyl groups only, the oxygen-plasma-formed oxygen functional groups were chemically reduced by diborane and LiAlH4 with yields of 10 to 11 OH groups per 100 carbon atoms in the 3 to 5 nm near-surface layer as detected by X-ray photoelectron spectroscopy (XPS). The identification of hydroxyl groups was performed by means of attenuated total reflectanceFourier transform infrared spectroscopy and XPS.
Several possibilities exist to produce a modified polymer surface with a high density of only one sort of functional group such as: (i) the plasma grafting of unfragmented monomer molecules and their polymerization forms OH, NH2, COOH groups, etc. in concentrations of approximately 25 groups per 100 C atoms; (ii) selective plasma bromination provides 1025 CBr groups; (iii) the plasma oxidation of polymer surfaces in an O2 plasma followed by the chemical reduction of all O-containing groups to OH groups by diborane, vitride (Na complex) or LiAlH4 yields 914 OH groups per 100 carbon atoms; and (iv) the grafting of spacers with different endgroups onto OH or CBr groups produces 710 spacer molecules/100 C. This work was focused on the formation of thin plasma deposited polymer layers with a maximum of (homo)functional groups and with a minimum of chemical irregularities using the pulsed plasma technique. The monomers were allylalcohol, allylamine, acrylonitrile and acrylic acid. The further intent was to study the interactions of functional groups (OH, COOH, NH2) and deposited metals (Cr, Al, Ti). It was expected that more basic (NH2), weakly basic or neutral (OH) or more acidic (COOH) groups would show different interactions and chemical reactions with metal atoms.